Rotary spray stencil apparatus and method



Oct. 31, 1967 R. G. DIIZDINGER 3,349,697

ROTARY SPRAY STENCIL APPARATUS AND METHOD Filed Nov. 5, 1964 4 Sheets-Sheet 1.

. l/VVE/VTOI? RHVMOND G. DID/N655 ATTORNEYS.

Oct. 31, 196 R. G. mmmcam ROTARY SPRAY STENCIL APPARATUS AND METHOD 4 Sheets-Sheet 2 Filed Nov. 5, 1964 Oct. 31, 1967 R DlDlNGER 3,349,697

ROTARY SPRAY STENCIL APPARATUS AND METHOD Filed Nov. 5, 1964 4 Sheets-Sheet 5 ATTORNEYS.

F/GL? Oct. 31', 1967 R DWG R 3,349,697

ROTARY SPRAY STENCIL APPARATUS AND METHOD Filed NOV. 5, 1964 4 Sheets-Sheet 4 x/vvnvro/e mama/v0 e. DIDINGER United States Patent 3,349,697 RQTARY SPRAY STENCIL APPARATUS AND METHOD Raymond G. Didinger, Folsom, Pa., assignor to Welded Tube Company of America, Philadelphia, Pa., a corporation of Pennsylvania Filed Nov. 5, 1964, Ser. No. 409,181 6 Claims. (Cl. 101-118) This invention relates to a marking apparatus and method. More particularly, this invention relates to an automatic marking apparatus and method responsive to the presence of the workpiece to be marked.

In the manufacture of elongated workpieces such as tubes, angle irons, I-bearns, etc., certain information is marked on the work pieces. For example, steel tubes have the following information applied thereon: size, gauge, length, raw material, alloy designation, product designation, heat number, lot number, and made in USA. This information is marked on the workpiece several times as the workpiece is coming to the end of the production line.

Heretofore, the information was applied to the work piece by an operator holding a stencil in one hand and a spray gun in his other hand. Since the workpiece is continuously moving, the operator walks along the production line with the workpiece while stencilling the information thereon. Thereafter, the operator walks back to his starting point and repeats the stencilling operation.

In the manufacture of many items such as steel tubes, conventional transfer roller techniques wherein a transfer roller picks up a stencilling medium and transfers it to the workpiece cannot be utilized. The reason for this is due to the fact that the workpiece is neither clean nor dry. Thus, when the workpiece is a hollow steel tube it is covered with cutting oil, chips, etc. The present invention is capable of eliminating the need for the abovementioned operator and does not require the workpiece to be precleaned.

It is an object of the present invention to provide a marking apparatus and method that is trouble free, inexpensive, and reliable for providing desired markings on workpieces.

It is another object of the present invention to provide apparatus and method for repetitively marking a moving work piece without relying on a transfer roller for applying the information on to the workpiece.

It is another object of the present invention to provide apparatus and method for automatically marking wet dirty workpieces of elongated lengths with desired information in response to the presence of a moving workpiece.

It is another object of the present invention to provide a marking apparatus and method which needs no supervision and is adaptable to mark desired information on elongated workpieces of substantially any cross sectional configuration.

It is another object of the present invention to provide novel apparatus and method of the class described in a manner whereby the marking cycle may be manually manipulated when desired.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there are shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIGURE 1 is a front elevational view, partly in section, of the apparatus of the present invention.

FIGURE 2 is a top plan view of the apparatus illustrated in FIGURE 1.

FIGURE 3 is a sectional view taken along the line 33 in FIGURE 2.

FIGURE 4 is a sectional view taken along the line 44 in FIGURE 1.

FIGURE 5 is a sectional view taken along the line 5-5 in FIGURE 3.

FIGURE 6 is a sectional view taken along the line 66 in FIGURE 1.

FIGURE 7 is a schematic wiring diagram for the apparatus illustrated in FIGURES 1-6.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIGURE 1 marking apparatus generally designated as 10 for automatically marking an article such as a hollow tube 12 with desired information while the tube 12 is moving to the end of the production line for the manufacture of the tube 12.

The marking apparatus 10 includes a movable frame 14 supported by a base designated generally as 16. The base 16 includes a base plate 18 which is adapted to rest on on the floor or any other convenient supporting surface. A hollow cylinder 20 is supported in an upright position above the base plate 18 by means of a strut 22 and rib 24. An elevating tube 26 on the frame 14 is telescopically received within the cylinder 20. A mechanical means is interposed between the elevating tube 26 and cylinder 20 for selectively elevating the frame 14 with respect to the base plate 18. As illustrated, the last mentioned means is a non-rising screw actuator 28 having a wrench engageable head 30.

The frame 14 includes a pair of spaced parallel support arms 32 and 34 supported in cantilever fashion by the elevating tube 26. As shown more clearly in FIG- URE 3, a platform 36 is fixedly coupled to the upper end of the tube 26 at the right hand end of the frame 14. Platform 36 is provided with an elongated slot 38 whose major dimension is parallel to the longitudinal axes of the arms 32 and 34.

A hydraulic means designated generally as 42 is supported by the plate 36. The hydraulic means 42 is coupled to a carriage designated generally as 40 for reciprocating the carriage toward and away from the path of travel of the tube 12. The carriage 40 includes a cylindrical body 44 having a forwardly extending base portion 46 as shown more clearly in FIGURE 4. The body 44 has a mounting block 48 thereon.

The hydraulic means 42 includes a horizontally disposed cylinder 52 having a front head 54 and a rear head 56 coupled by bolts to the platform 36. A piston rod has one end threadably coupled to the mounting block 48 and has its other end (not shown) coupled to a piston disposed within the cylinder 52. Hydraulic motive fluid, such as pressurized air, is supplied to the front head 54 by conduit 53 and to the rear head 56 by conduit 60.

The carriage 40 is guided at its sides by any convenient surface for reciprocation toward and away from the path of travel of the tube 12. Such movement is initiated by the piston rod which in turn is guided in its movement and thereby guides the carriage 40. In the illustrated embodiment, the rear end of the carriage 40 is supported by the piston rod 50. The forward end of the carriage 40 is supported by an arm 62 connected to the upper surface of base portion 46. Arm 62 is slidably supported by a strut 64 extending between the support arms 32 and 34.

A microswitch 66 is adjustably supported by a hollow brace 68 on the lowermost surface of the base portion 46. Microswitch 66 is mounted for movement with the carriage 40. Microswitch 66 has an actuator 70 terminating in a cam follower 72. Cam follower 72 is in rolling engagement with a cam 74. The cam 74 has a cam portion 76 and the balance of its periphery is a dwell portion.

The cam 74 is supported for rotation about an upright axis by shaft 78. Shaft 78 is threadably coupled to the base portion 46. A gear 80 is supported above the cam 74 by the shaft 78. The pins 84 couple the cam 74 to the gear 80 for rotation therewith. A hearing sleeve 82 is provided between the gear 80 and the base portion 46.

The gear 80 is in meshing engagement with a gear 85 on the lower end of an upright main shaft 86. The main shaft 86 is surrounded by a bearing sleeve 88 and disposed within the cylindrical body 44.

A hub 92 is connected in any convenient manner, such as by a set screw, to the upper end of main shaft 86. The hub 92 is supported by a bearing plate which in turn is supported by the body 44. A wheel designated generally as 94 is supported by the shaft 86. Wheel 94 includes the hub 92 as Well as upper rim 96 and lower rim 98. The rims 96 and 98 may be annular tubes as illustrated and interconnected with struts 100 at spaced points therearound. As shown more clearly in FIGURE 6, the struts 100 may be V-shaped members. The lower rim 98 is coupled to the hub 92 by spokes 99.

A skin 102, such as sheet metal, is fixedly secured to the outer periphery of the rims 96 and 98. As illustrated, the wheel 94 lacks a bottom wall. If desired, a wall could be provided by securing a layer of sheet metal in the form of an annular disc to the spokes 99.

As shown more clearly in FIGURES 3 and 6, the skin 102 is provided with an elongated peripheral slot within which is removably disposed a stencil 104. The stencil 104 may have cutout portions corresponding to the information desired to be applied to the tube 12. Resilient metal clips 106 may be provided to retain the stencil 104 over the slot in the skin 102.

A spray gun 108 is fixedly supported within the wheel 94. Spray gun 108 has a flexible conduit 110 coupled to a source of stencilling fluid such as paint. Spray gun 108 also has a flexible conduit 112 coupled to a source of motive fluid such as pressurized air. It will be noted that the nozzle 114 on the spray gun 108 is directed toward the stencil 104 and the path of travel of the tube 12.

An adjustable knob 116 is provided on the spray gun 108 for retaining a support rod 120. The support rod 120 has one end adjustably coupled to an adapter on the body 44 (see FIGURE 4). The rod 120 extends through a guide 122 on the platform 36, extends upwardly over the rim of the wheel 94 and then downwardly into the wheel 94 for releasable connection to the spray gun 108 by means of the nob 116. An adapter is supported by the rod 120 which in turn supports a paint brush or the like 124. The bristles on the brush 124 are positioned so that they engage the inner periphery of the stencil 104- each time that the stencil 104 passes by the position of the brush 124.

As shown more clearly in FIGURES 2, 3 and 4, a plate member 126 is supported by the support arms 32 and 34 and fixedly coupled thereto by means of bolts 128 and 128. The plate member 126 extends at an angle from the support arm 34 with respect to the path of travel of the tube 12. An upright pin 130 is supported at the terminal end of the plate member 126. An arm 132 is rotatably supported by the pin 130 and biased in a counterclockwise direction in FIGURE 2 by means of spring 134.

The free end of spring 134- is fixedly coupled to an upright post 136 on the platform 36. Arm 132 includes a wiper holder 138 supporting at its terminal end a wiper 140. Spring 134 biases arm 132 and wiper 140 in a counterclockwise direction in FIGURE 2 so that the wiper 140 may wipe away excess liquids on the tube 12 before the information is marked on the tube 12.

As shown more clearly in FIGURES 1 and 2, a platform 142 is supported by the terminal ends of the cantilever support arms 32 and 34. A microswitch 144 having an on-ofl button 146 is supported on the platform 142. A rotatable actuator arm 148 is provided for the button 146. The free end of the arm 148 terminates in a roller in abutting engagement with a trigger 150 in the form of a plate. The trigger 150 is rotatably supported by upright pin 152. Trigger 150 is provided with an extension lever 151 which is biased against limit stop 158 by means of spring 154. Spring 154 has one end coupled to the extension lever 151 and has its other end coupled to a post 156. Spring 154 biases the trigger 150 to the position illustrated in FIGURE 2.

In FIGURE 7, there is illustrated a schematic wiring diagram for the apparatus 10. Current is supplied to the apparatus 11 by conductors 160 and 162. Conductors 164 and 166 couple the microswitch 144 across the conductors 160 and 162. Conductor 166 is coupled through a three position switch 168 and has an on-off switch 170. Switch 170 is preferably a normally open switch which is closed only when the production line for the article such as tube 12 is in operation.

Electrical potential is coupled from the switch 144 by Way of conductors 172 and 174 to solenoid 176 on a four way valve 178. Conductor 172 has a limit switch 184. Valve 178 controls the supply of motor fluid such as pressurized air from conduit 180 to the conduits 58 and 60 of the hydraulic means 42. Conduit 180 may have a pressure regulator 182 therein.

Switch 66 is coupled across the switch 144 by means of conductors 186 and 188. A solenoid on valve 190 is coupled to the conductor 186 in series with switch 66. Valve 190 selectively controls discharge from nozzle 114 on the spray gun 108. Valve 190 has an exhaust vent 194.

Conduit 112 is preferably coupled to a source of pressurized air as pointed out above. A branch conduit 192 extends from conduit 112 to a pump 196. When actuated by pressurized air from conduit 192, pump 196 pumps a stencilling fluid, such as enamel paint, from tank or drum 198 through filter 200 in conduit 110 to the spray gun 108. Pump 196 could be an electrical rather than hydraulic pump if desired.

Valve 178 has a second solenoid 206. Solenoid 206 and limit switch 208 are coupled across the switch 144 by conductors 202 and 204. As shown more clearly in FIG- URE 4, the followers and 209 on the limit switches 184 and 208, respectively, are actuated by a cam plate 210 on the carriage 40. As illustrated in FIGURE 4, switch 184 has been tripped thereby opening the circuit to solenoid 176 to shut off the supply of motive fluid from conduit 180 through conduit 60 to the cylinder 52. Thus, the carriage 40 is in its forward position.

The remaining elements of the present invention not heretofore described will be brought out more clearly in connection with the following description of operation.

Let it be assumed that the marking apparatus of the present invention is to be utilized to mark desired information on a hollow metal tube having a substantial length such as thirty feet. Further, it will be assumed that it is desired to have the information marked on the tube 12 at spaced intervals of about ten feet. The stencil 104 will have been prepared with appropriate openings corresponding to the desired information to be stencilled.

When the conveyor means of the production line for the manufacture of the tube 12 is started, switch 170 will be closed and switch 168 will be on its automatic position. The tube 12 moves along its intended path corresponding to the direction of the arrow 222 in FIGURE 7. As the tube 12 moves along its path, it abuts the trigger 150 and rotates the same about the longitudinal axis of pin 152. Such rotation of the trigger 150 closes the normally open switch 144. As a result thereof, electrical potential is coupled from conductors 160 and 162 through switch 144 and along conductors 172 and 174 to the solenoid 176. Limit switch 184 is normally closed. Hence, solenoid 176 is activated to shift the valve member of valve 178 so that motive fluid is directed from conduit 180 through conduit 60 to the cylinder 52.

The motive fluid introduced into the cylinder 52 reciprocates the piston therein to the left in FIGURES 1 and 7 thereby moving the carriage 40 until limit switch 184 is tripped by the cam plate 210. When switch 184 is tripped, the circuit is broken and the wheel 94 will have been moved to its forward position wherein the periphery of wheel 94 is in rotative engagement with the outer periphery of the tube 12 as illustrated in FIGURE 1. Since the tube 12 is moving along its production line, it rotates the wheel 94 in a counterclockwise direction in FIG- URE 2.

Rotation of the wheel 94 causes the shaft 86 and its gear 85 to rotate. Since cam 74 is coupled to gear 80 which in turn is meshed with gear 85, the cam 74 rotates. The follower 72 follows the contour of the cam 74. When normally open switch 66 is actuated by contact between follower 72 and cam portion 76, current is coupled through conductors 186 and 188 to the solenoid on valve 190. The opening of the valve 190 enables air from conduit 112 and paint from conduit 110 to be discharged from the spray gun nozzle 114 through the stencil 104 onto the outer periphery of the tube 12. At this point in the cycle, the stencil 104 will be between the nozzle 114 and the tube 12 and rotating with wheel 94. Such spraying will continue until the follower 72 is in engagement with the dwell portion on the cam 74. Paint brush 224 Wipes the stencil 104 to keep it clean. Thereafter, switch 66 will open the circuit and valve 190 will close.

It will be noted that the gear 85 is substantially smaller than the gear 80. Accordingly, the wheel 94 will continue to be rotatably driven by the moving tube 12 until the follower 72 is again in contact with the cam portion 76. As a result thereof, the spraying cycle will be repeated so that the tube 12 is again marked with the identical information. This cycle will automatically repeat itself so long as a tube 12 is biasing the trigger 150 in a clockwise direction in FIGURE 2. Normally, a second tube immediately follows a previous tube so that trigger 150 is not permitted to resume the position illustrated in FIG- URE 2. As soon as there are no more tubes moving along the production line, trigger 150 is free to rotate to the position in FIGURE 2 by the bias of spring 154. When this occurs, current is coupled by way of conductors 202 and 204 to the normally closed limit switch 208 and to solenoid 206. Activation of solenoid 206 causes motive fluid to flow from conduit 180, through valve 178, through conduit 58 to the cylinder 52. This results in the carriage 40 being reciprocated to the right in FIGURE 2 until limit switch 208 is tripped thereby interrupting the circuit. The components will remain in this position until trigger 150 is again activated by a tube 12 moving in the direction of arrow 222. When tube 12 or other articles cease to be moving along the production line, switch 170 will be open.

Whenever the production line is stopped with a tube in position so as to be in engagement with the periphery of the wheel 94, switch 212 in conductor 214 is automatically closed. As a result thereof, solenoid 206 is activated by a potential carried along conductor-s 214 and 216 to retract the carriage 40 until limit stop 208 is tripped to open the circuit.

When the production line is stopped, it is desirable to test the apparatus to be assured that the closing of normally open switch 66 is properly synchronized with the position of stencil 104, and to provide for cleaning of the spray gun 108. A manual operation is provided for. Thus, the bottom half of switch 168 is manually activated to couple current through conductors 218 and 220 to the solenoid and valve 190 and switch 66. Thereafter, the wheel 94 may be manually rotated to effect a spraying action each time that the follower 72 engages the cam portion 76. Thus, it will be noted that switch 168, of conventional construction, has an automatic position, a manual position and an off position.

Thus, it will be seen that the present invention includes circuitry for enabling a stencilling medium such as paint to be sprayed on the moving workpiece, such as tube 12, in timed relation with respect to rotation of wheel 94 whereby the stencil 104 is positioned by wheel 94 in juxtaposition to the nozzle 114 every time the stencilling medium discharges from nozzle 114. The mounting means for cam 74 is simple and within easy reach so that a different cam may be substituted when a change of the cycle is desired or required by a stencil of different length. If desired, the coupling between cam 74 and gear may be made adjustable by means of conventional structure to provide accurate control of synchronization.

The apparatus 10 has been constructed and tested and found to provide trouble free, reliable, inexpensive marking of steel tubes. The operation was automatically effected while marking dirty tubes covered with cutting oil. Large pools of the cutting oil are removed from the side of the tube 12 by means of a wiper 140. Otherwise, no precleaning of the tube 12 was required. Experience has shown that no supervision is required once operation is initiated.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

1 claim:

1. A marking apparatus comprising a carriage, a wheel rotatably supported by the carriage, hydraulic means for moving the carriage from an inoperative position to a workpiece engaging position and vice versa, said wheel having a periphery adapted to be in contact with a moving workpiece whereby the wheel may be rotated by the workpiece, a trigger in the path of movement of the workpiece so as to be contacted and pivoted by the workpiece, a spray gun supported by said carriage and disposed within said wheel for spraying at least one medium through a stencil supported by the wheel covering only a portion of said wheel onto a moving workpiece, said trigger being coupled to circuitry for actuating said bydraulic means, and means including said circuitry for controlling spraying of a medium through the spray gun and stencil in timed relation with respect to rotation of said wheel whereby the stencil is positioned by the wheel in juxtaposition to the nozzle and workpiece every time the medium discharges from the nozzle.

2. Apparatus in accordance with claim 1 wherein said circuitry includes manual means for selectively causing a discharge of the medium from the nozzle in the absence of a workpiece in engagement with the periphery of the wheel.

3. Apparatus in accordance with claim 1 wherein said means including said circuitry further includes a cam coupled to said wheel for rotation in timed relationship therewith, and a switch structurally interrelated with said cam and a valve on said spray gun.

4. Apparatus in accordance with claim 1 including a wiper biased to a position for engagement with the workpiece prior to contact between the workpiece and the periphery of the wheel and means for wiping the stencil to clean the same after the medium has been sprayed through the stencil.

5. A method comprising the steps of moving a workpiece past a marking station, causing the workpiece to engage and pivot a trigger as it moves past the marking station, moving a marking wheel into engagement with the moving workpiece in response to movement of the trigger, causing the workpiece to rotate the wheel, mounting a stencil on the wheel so that it covers only a portion of the wheel, periodically marking information on a workpiece by spraying material from inside the wheel through openings of the stencil onto the workpiece, and initiating such spraying as a function of the position of the wheel.

6. A method in accordance with claim 5 including wiping the stencil after each cycle to clean the same and wiping the workpiece prior to contact between the workpiece and the wheel.

References Cited UNITED STATES PATENTS 537,923 4/1895 Hildyard 1011 15 632,527 9/1899 Hey 101234 767,684 8/1904 Burdick 101115 1,910,461 5/1933 Bower 10*l37 X 2,237,179 4/1941 Gromm 10l116 2,641,998 6/1953 Donald 101235 2,928,340 3/1960 Stein et al. 1011l5 X 3,129,442 4/1964 Leckie 101-129 X ROBERT E. PULFREY, Primary Examiner.

H. P. 'EW'ELL, Assistant Examiner. 

5. A METHOD COMPRISING THE STEPS OF MOVING A WORKPIECE PAST A MARKING STATION, CAUSING THE WORKPIECE TO ENGAGE AND PIVOT A TRIGGER AS IT MOVES PAST THE MARKING STATION, MOVING A MARKING WHEEL INTO ENGAGEMENT WITH THE MOVING WORKPIECE IN RESPONSE TO MOVEMENT OF THE TRIGGER, CAUSING THE WORKPIECE TO ROTATE THE WHEEL, MOUNTING A STENCIL ON THE WHEEL SO THAT IT COVERS ONLY A POR- 